peavey heritage vtx mods

OK, it's decided.  This project is hereby named "Heavey".  After lugging this durned thing 1400 miles up to Seattle, yes, I can attest, there is no better name for it.  Even with one speaker removed.  Still too "heavey".  Takes a lot of heaving.  Ugh. And of course, I had to make an official logo for it, because that's how I am: Ta da. To make this logo, I took an existing Peavey logo (off another amp, since it was missing on the VTX in question) and photocopied it.  Then I printed out a pagefull of 1mm grid squares (with the 10mm lines thicker, for reference).  I.e., "graph paper".  Then I lined the two sheets up and used a sharp point to poke through both sheets at all the corner points of the Peavey logo.  This allowed me to take-off the coordinates of the points, to 0.5mm precision.  I put these into a PostScript file, and then made some minor visual adjustments until it looked right.  Then, I printed the reconstructed logo...

  Opened the unit up, to survey work to be done.  While in there, I took the opportunity to unplug the "ground polarity" switch (aka death-cap switch).  Amazing that they still had those, in what I'd estimate to be the early 1980s. The way the speaker baffle is made, it's glued into routed slots, so I think it would be difficult to fully remove (to convert to a 1x12).  So instead, I'll cut most of it away, leaving a lip around the edge, and then attach a second layer of plywood onto that lip.  The speaker will be inset rather than top-mounted as they are now, and I suppose I'll use my usual sandwiched metal grate speaker grille instead of the Peavey plastic-fabric grille.  The current velcro-on grille frame has been rebuilt by somebody, rather inexpertly.  That's part of why there's no Peavey logo. I'm still not sure if I should call this "Heavey", or "Peavish".  It's so damn heavy that it peeves me, so could go with either....

OK, that was successful, I've got the footswitch operating the way I want now.  Added benefit is to verify the same wiring I plan to use with the front-panel switches (shared ground, etc.).  Everything seems to work fine. As mentioned, the functions are now button 1 = "norm gain", button 2 = "lead gain", and button 3 = reverb. Amusingly, I almost convinced myself I had wired something wrong, because I never really noticed and internalized, until now, that the "lead" channel is the first one (leftmost on the panel), followed by the "norm" channel in the middle.  Worse yet, "lead" has a green LED, whereas "norm" has a yellow LED!  This is all backwards from most "standard" amps nowadays (even ones from Peavey).  So I almost tore into the plug and started rewiring it again when I saw green where I expected yellow, etc., but fortunately I clued in just in time.  Weird, I might have to swap those LED colours...

  Here is what I've determined about the wiring of the footswitch and DIN plug, along with the changes I'm proposing to make, to render this three-button footswitch more useful for me. After this rewiring, button 1 will select the "norm" channel, button 2 will select the "lead" channel, and button 3 will select reverb.  There will no longer be control of the phaser.  There won't be a "combine" button per se (since these switches are SPST, not SPDT); instead, the two channels will have independent selection, allowing both to be on at once if desired.  (Also there will be a new both-off mode, maybe useful as a mute function.) The original four-button footswitch apparently used the cable shield as a different ground for the channel selection, while using pin 1 as ground for the reverb and phaser.  I'm guessing this had to do with noise issues.  I'm hoping there wasn't an actual DC voltage other than 0 on either "ground" line,...

OK, another less-than-ideal "surprise" from this old VTX amp.  Yes, it came with *a* footswitch; but not the right one.  Having only three buttons instead of four was, I suppose, a giveaway. Turns out, this footswitch can only control the reverb and the phaser (and the third button does nothing).  It's from some other Peavey amp, I guess.  Same unusual DIN-type connector, so I could even theoretically make it work fully, by drilling a hole for a fourth switch.  Or, I wouldn't mind if a single switch ("effects") controlled both reverb and phaser.  In all likelihood, I'll use the phaser almost never, and if I do, it would likely be for some weird sound experiments in a recording, not live.  But it's a real drawback that there's no footswitching for the two channels: which would need two buttons, to permit the unusual "combined" mode which Peavey makes available. Yep, I think I may as well rewire this three-button footswitch so that it can...

  I'm finally back in San Diego where I've been keeping this VTX amp, so I can get a look at it and start to map out the transformation process in earnest.  There have been a few surprises already... At least I have the footswitch; couldn't remember if I had it or not.  Regardless, I'll be putting in panel switches so that the footswitch is not required. I had wisely already added some wheels to this amp.  My my, but it's heavy!  WTF, Peavey? As you can see, someone before me has changed both of the speakers.  Guess they didn't care for the tone -- I sympathize, but I doubt this helped much.  The one which is not blown is a Celestion G12L-35.  I presume that means it's rated for 35W.  It's too bad, because the original Peavey Scorpions or Black Widows or whatever, which the amp came with, would have been rated (I think) for over 100W each.  So even with one blown, I could have changed this amp into a 1x12, with no issues from the 4x6L6 p...